The objectives of this research are as follows: (1) To gain knowledge on the native molecular weight, subunit structure, shape, and conformation of the isolated native ribosomal proteins which have particular functional role in the self-assembly of the ribosome and in the involvement of ribosome in protein synthesis. Proteins S4 and S8 are selected for the former studies, and proteins L7 and L12 for the latter. (2) To study the change of these structural parameters as a function of the environmental factors critical to self-assembly and the function of the ribosome. (3) To elucidate the mechanism of protein-RNA interactions by studying the conformational change of the RNA on protein binding employing circular dichroism, and conformational change of the protein by fluorescence measurement. The protein S4-16S RNA and the protein S8-16S RNA interactions will be investigated. Our overall objective is to adopt these physico-chemical methods to elucidate the structure of the proteins and their interactions with RNA so as to understand the general principles and mechanism of this protein biosynthetic machinery. We confidently expect to contribute significantly to the detailed knowledge of protein biosynthesis which is a prerequisite for understanding its many types of regulations and to the many biomedical problems associated with them.